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Michael Moore
Category: Chevy
Satisfied Customers: 2956
Experience:  ASE Master/GM WORLD CLASS/GM Master/GM ASEP/Dodge Gold/Mazda cert.
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P2135 Pedal Position Switch A/B Voltage Connection error -

Customer Question

P2135 Pedal Position Switch A/B Voltage Connection error - do you just buy a new switch and replace it. We have got this error 2 times in the last month. Have an under the dash error reader. The truck looses all power and you basically have to pull over and shut it off for awhile. It always works fine when you start back up and continue driving. It is actually a GMC Yukon 2004.
Submitted: 8 years ago.
Category: Chevy
Expert:  Michael Moore replied 8 years ago.
I have had many of these trucks with this concern. The most common problem found is the wiring connector at the throttle body on the engine. The wires break inside the connector and the reduce engine power light will come on in the dash. GM has a bulletin, tells you to check the wires comming from the throttlebody. Pull onthe wires at the connector to see if there broken, if they are, replace the connector. The bulletin will tell you not to replace the connector, may cause other codes. I have never had this happen, i have always replaced the connector and fixed the problem. You can get the connector at your local dealer, they should have one instock.

#PIP3089B: SES Light And Reduced Engine Power DTC P0120 P0220 P1516 P2135 - keywords accelerator actuator APP blade body connector connection DTC L33 L59 LH6 LR4 LM7 LS1 LS2 LQ4 LQ9 module position reduce sensor - (Oct 31, 2006)
Subject:SES Light and Reduced Engine Power DTC P0120 P0220 P1516 P2135
Models:2004-2006 Buick Rainer
2005-2006 Cadillac CTS-V
2003-2006 Cadillac Escalade
2003-2006 Chevrolet Avalanche, Corvette, Express, Monte Carlo, Silverado, SSR, Suburban, Tahoe, Trailblazer
2003-2006 GMC Envoy, Savana, Sierra, Yukon
2003-2006 Hummer H2
2005-2006 Pontiac GTO
Equipped with a 4.8 5.3 6.0 or 7.0 V-8 Engine

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.


A vehicle may be brought into the dealer for a reduced power message, and DTCs P0120, P0220, P1516, P2101, or P2135.

The Throttle Actuator Control (TAC) / throttle body type trouble codes, may be caused by a loose wiring crimp at the throttle body connector,
or a broken throttle body circuit.


Complete the current SI diagnostics for any symptoms or trouble codes found. If a intermittent T/P or TAC module type code is occurring complete the inspections below.

  1. Inspect all related throttle body terminals for a loose wiring crimp. The loose crimp may be difficult to find, and the poor connection will be between the terminal and the copper strands of the wire. Wiggle test the individual throttle body circuits to see if the concern can be duplicated.
  2. Inspect the related circuits for broken wires inside the insulation. The outer wire insulation may look fine, but the internal copper strands may be partially broken. Breaks in the wires usually occur within 1 to 4 inches of the throttle body connector. Wiggle testing may also induce a trouble code to set.
  3. On C/K trucks complete SI procedures for voltage drop on grounds G103 and G104. Grounds G103 or G104 may be loose or corroded.

If a terminal crimp or a broken wire has been found, repair or replace only the circuits involved. There is a throttle body pigtail connector available through GMSPO, but installing this pigtail connector may cause other intermittent TAC module/TP codes at a later date. If this pigtail must be used, please follow the SI procedures for Splicing Copper Wire Using Splice Sleeves. (the proper Kent-Moore crimping tool must be used for this repair)

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.



Michael Moore and 3 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.

So your saying that in most cases it is a loose wire crimp. I did check that. There is very little reason that the wires would be broken or even moved, there has never been any movement of anything in the engine compartment since we owned it, no one moving any wires or harnesses for any reason. Just oil air filter changes, etc. No problems of any kind until this.

What would cause a loose wire crimp, gravity?


Expert:  Michael Moore replied 8 years ago.
What i find is a vroken wire, it may look like the wire is ok, but under the insulation, the wire is broken. GM has had many issues with there sensor wires doing this. Its the vibration of the engine that causes this concern.